Electric fluid heater temperature control



Nov. 14, 1933. G. E. WHITE ELECTRIC FLUID HEATER TEMPERATURE CONTROLFiled July 30, 1932 mventor Gerald E. wlz' 'e Gttorneg Patented Nov. 14,1933" Y A y i {Uixu'i-ED STATES PATENTf OFFICE ELECTRIC FLUID HEATERTEMPERATURE 1 CONTROL Gerald E. White, Lansing, Mich.`

Application July 30, 1932. Seriall No.'626,995

5 claims. (o1. 21e- 39) This invention relates to electric fluid heaterany further decrease in the' temperature will temperature controls mostcommonly used in cause it kto operate and: close the electricalcirconnection with electric water heaters, and is cuit, and by thismeans a Very close temperature intended as an improvement of theapparatus control can be maintained.

5 for like purposes illustrated and described in It will be seen that ifyfor any reason the water @o Letters Patent of the United States issuedto or matter being heated by the unit be drained this applicant andnumbered 1,854,322, dated away from the unit the controlling deviceswill April l19, 1932. j continue to operate and protect the unit fromThe primary object of this improvement is excessive temperatures. yIftheheating surface 1()` believed to be attained by the special construcofVthe, unit becomes covered with lime or scale tion and arrangementherein vset forth and so that the heat cannot be conducted to theclaimed, which is thought to create a heat conwater as rapidly as itshould, the controlling detrolled `device which will besure of operationin-k vice will protect the unitY and prevent it from dependent of thetemperature of the water or becoming overheated. p

matter to be heated by the heating devices. The special constructicn andcombination of 7c There is a controlling device which controls the theparts of this vinvention are illustrated in the temperature of theheating unit itself. By this accompanying drawing, of which Fig. 1repremeans the heating unit will be Aprotected from sente a verticalsectional' View` of all parts asexcessively high temperatures thusinsuring a sembled.` FigZ is avertical sectional view of 204 long lifefree from interrupted service. conthe heating chamber or box and theenclosed 75 trolling device fashioned according to this in- Compartmenttherein.` Fig. 3 is a V,vertical secvention will, it is believed,accomplish the stated 'GOlial View 0f the diaphragm bOX and Switch 0215.objects for the following reasons: The enclosed Fig- 4 ShOWS fil-DG"dial, adjustment p'OIler and chamber 'which may be an integral Vpart ofthe S0211@ with@ CaSe. v

heating tank is provided with an enclosed com- ThIOUghOUG thedeSClptiOIl and dmwingthe 80 partment, which may be an integral part ofthe same number is used to refer to the Same pari. chamber ory heatingunit or so closely adjacent to COIlSidelilg the drawing, 8 tank 1 Ofany01105611 the heatingunit as to maintain the temperature fOIm has 9JdiSCharge pip? 2 With balihei 3 and in direct proportion to that of theheating unit 4 passing GhlOlle'h the bOOm 5 Of A the tank.

irrespective of the temperature of the water or Erected on the bottom 5isrthe heating unit 01' 85 matter which the unit is heating. The saidenchamber 6, usuallyicrmed with a vertical central closed compartment isto contain a liquid or a passage 7. This invention is not limited t0 thegas or both, which will expand or contract in particular shape Of hChamb-I 6. F'Olmed With accordance with the temperature of the heatingthe chamber or adjacent thereto is a compartunit ,The expansion 0rcontraction 0f the liquid ment 8, and from the compartment extends atube 9.0 or gas'can be made to move a bellows diaphragm 9 t0 aneXpariSible diaphragm 10I WhiCh may be or similar device, or otherarrangement, which COllapSSd by the Spring 11', both Within the diacanbe constructed to Ymake and break an elecphiagm bOX 12 The SpringSurrounds ai 1`0d 13 tric circuit which will'control the temperatureattwhed t0 the diaphragm, and 'the T Od isvcon- 4.0 of the heating unitvA vel-y C105@ Control of nected with apivoted switch arm 14 carrying a95 the temperature of the heated water or other mercury SWiCh l5. TheCOIlduCOlS 16 and 17 are matter can be maintained by this type of con-Shown connected with the switch. The conductrol without the use of verydelicate mechanism, ductors leadlikewise to coils 18 as best shown inbecause oi the fact that the enclosed compart- F'igl- SWiCh arm 14 iSSilppOied upOIl a piVOi ment of the chamber containing the expanded 19carried by a revoluble disk 20 on arbor 21, 100 liquid or gas will whenthe heating unit is in which as best showin in Fig. 4 carries thepointer operation, be at a higher temperature than the 22 arranged tosweep scale 23. The coil 18 may water or matter being heated. Theresults will be wound upon a glass or other partition 24 in be that whenthe electric current supplying the the compartment 8.

; unit is disconnected or interrupted the tempera- The operation isthought to be manifest from 105 ture of the enclosed compartment candrop to the drawing and explanation. Branch tubes 3 that of the heatedwater without any drop in and 4 drain the tank into the tube 2, branch 4takthe temperature of the water itself. This will ing :duid from theVertical passage '7. cause the expanded liquid or gas to contract and Asshown in Fig. 3, disk 20 may be an eccenthe controlling device can be soadjusted that tric, and in the Fig. 4 the pointer occupies a mid- 11,0

dle position upon the scale. Let it be assumed that the pointer in Fig.4 is turned to the left to 90 of the scale. Pivot 19 would be raised andarm 14 tilted down. 'Ihe mercury in switch 15 would run from thecontacts and the circuit would be broken. If, however, coil 18 and itscompartment 8 cooled down, the contracting diaphragm will tilt theswitch arm up and re-establish the current. The arm will be tilted downagain as the heat increases and the current again interrupted, so thatthe temperature will be kept at approximately the desired 90.

Conversely, if the pointer in Fig. 4 is turned to the right, the diskwill carry the pivot of the switch arm downwardly as will be readilyseen from Fig. 3, and its free end will be tilted upwardly causing themercury to run to the contacts of the conductors 16 and 17. The heatingwill increase and will continue until such a temperature is reached aswill so expand the diaphragm as to force the end down sufficiently tobreak the circuit. As the parts are designed and associated thisbreaking of the circuit will occur before excessively overheating thecoil or chamber, and the heat of the chamber and coil will fall to thatof the water in the tank. The various parts illustrated and describedare carefully proportioned, and the desired temperature may be closelyregulated to any degree of the scale.

Having now described this invention and the manner of its use, I claim:-

1. In an electric fluid heater temperature control, the combination witha tank, of a heating chamber therein, an electrically energized coil,the said chamber having a compartment for the reception of the coil, thesaid chamber having a vertical fluid passage, the said tank having tubesconnected with the interior of the tank outside said heating chamber andwith the vertical passage thereof, an expansible diaphragm device, atube connecting said compartment of the chamber and the said diaphragm,an electric switch controlled by the movements of the diaphragm wherebythe contraction of the diaphragm impresses a closing movement upon theswitch, and meansfor regulating the opening and closing of the switchwith respect to the expansion and contraction of the diaphragm.

2. In an electric fluid heater temperature control, the combination witha tank, of a heating chamber therein, an electrically energized coil,thesaid chamber having a compartment for the reception of the coil, anexpansible diaphragm device, a tube connecting said compartment and thesaid diaphragm, an electric switch controlled by the movements of thediaphragm, said switch being constructed to open and close by a tiltingmovement whereby the` contraction of the diaphragm impresses a tiltingclosing movement upon the switch, and means for regulating the tiltingmovements of the switch with respect to the expansion and contraction ofthe diaphragm.

3. In an electric fluid heater temperature control, the combination witha tank, of a heating chamber therein, an electrically energized coil,vthe said chamber having a compartment for the reception of the coil, anexpansible diaphragm device, a tube connecting said compartment and thesaid diaphragm, a tilting electric mercury switch controlled by themovements of the diaphragm whereby the contraction of the diaphragmimpresses a tilting closing movement upon the switch, and means forregulating the opening and closing tilting movements of the switch withrespect to the expansion and contraction of the diaphragm.

4. In an electric iiuid heater temperature control, the combination witha tank, of a heating chamber therein, the said chamber having acompartment, an electrically energized coil in the said compartment, thesaid chamber having a vertical passage, the said tank having tubesconnected with the interior of the tank outside the heating chamber andwith the vertical passage thereof, an expansible diaphragm device, atube connecting the said compartment of the chamber and the saiddiaphragm, a tilting mercury electric switch, a pivoted arm carrying theswitch and controlled by the movements of the diaphragm whereby thecontraction of the diaphragm impresses a tilting closing movement uponthe switch, means for adjusting the pivotal support oi said arm andregulating the opening and closing movements of the switch with respectto the expansion and contraction of the and a scale and pointer forindicating the temperature in accordance with the position of the pivotof said switch arm.

In an electric iiuid heater temperature control, the combination with atank, of a heating chamber therein having a compartment, an electricallyenergized coil arranged to heat the said compartment and the walls ofsaid chamber, the said chamber having a vertical passage, tubular meansconnecting the interior of the tank outside the heating chamber with thesaid vertical passage, an expansible diaphragm device, a tube connectingsaid compartment and the diaphragm whereby the expansion by heat of thecontents of said compartment and the contraction thereof arecommunicated to the diaphragm, a rod attached to the said diaphragm, anelectric switch device having an arm pivotally attached to the said rod,revoluble means pivotally connected with said arm and adapted to adjustthe inclinatory position of the arm, a pointer actuated by the movementof said revoluble means, and a scale arranged to be swept by saidpointer.

GERALD E. WHITE.

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